Pump

ABSTRACT

A dual-function pump assembly for pumping liquid with solid contaminants. The primary portion or section of the pump pumps liquid from an inlet to an outlet across a self-cleaning wash flow filter to a location of use. The secondary portion or section pumps clean liquid, which has passed through the filter, to lubricate and purge the running clearances and rubbing surfaces of the assembly.

I U mteti States Patent [151 3,639,089

Lock Feb. 1, 1972 [54] PUMP 3,250,460 5/1966 Cassidy et al. ..4l8/93 X [72] inventor: Thomas Lock, Parma Ohio 3,223,044 12/1965 Adams et al. ..4l8/268 X [73] Assignee: Borg-Warner Corporation, Chicago, lll. Primary Examiner-Robert M. Walker [22] Filed, Mar 26 1970 Attorney-Donald W. Banner, William S. McCurry and John W. Butcher [21] Appl. No.: 22,964

, [57] ABSTRACT [52] US. Cl ..4l8/93, 4l8/268 A malfunction pump assemmy f pumping liquid with Solid [51} hit. Cl. ..F0lc 21/06,F03C 3/00 Comaminants The primary Pol-ion or section of the pump [58] Fleld 0 Search 94, 818, 89,98, 103, p p from an inlet to an Outlet across a Self c|eaning 4 8/91 268 wash flow filter to a location of use. The secondary portion or v. section pumps clean liquid, which has passed through the [36} References cued filter, to lubricate and purge the running clearances and UNITED STATES PATENTS rubbing surfaces of the assembly.

2,827,226 3/1958 McCormack ..41 8/93 4 Claims, 2 Drawing Figures canoe 22 Q 2 RF: 18

PATEMTED FEB I972 am's pag n 2 INVENTOR THO/M45 40cm ATTORNEY PUMP BACKGROUND OF THE INVENTION When pumping liquids which may contain solid contaminants there is the need to lubricate and purge the running clearances and rubbing surfaces of the pumping assembly. This requires clean filtered liquid so as to eliminate or materially reduce the occurrence of abrasion and damage from the solid contaminants.

One arrangement for lubricating running parts of a pump assembly is described and claimed in Turner et al. US. Pat. No. 3,450,052. In this patent, the journals of the gear pump are formed with grooves and thus function as metering pumps. The flow of lubricating liquid is from the filter to the gear pump inlet and then to the gear pump outlet.

THE INVENTION According to this invention, a dual function pump is ineluded in a pumping assembly, a primary portion or section of which pumps contaminated liquid from its inlet to its outlet and across a self-cleaning wash flow filter to a location of use. A secondary portion or section of the dual function pump has its inlet connected to withdraw clean liquid which has passed through the filter and pumps this liquid to the various areas of the assembly for lubrication and purge of the running clearances and rubbing surfaces thereof. The flow of clean liquid is then into the flow path of the primary portion of the dual-function pump.

A lobe pump having a plurality of blades, which move by centrifugal force, by pump hydraulic pressure and a cam ring, in suitably disposed radial or substantially radial grooves in a rotor performs as a dual function pump. To provide the dual function, additional ports are located in the bearing sidewalls of the pump to utilize the lower portion of the blades and the rotor slots as the secondary portion or section of the pump. To enhance the purging action of the clean liquid and for lubrication and hydraulic balance each blade may consist of an assembly of vanes having beveled edges. For hydraulic balance of radial pressure loads, the pump may be of a double lobe construction.

THE DRAWINGS FIG. 1 is a sectional view of the pump assembly constructed according to this invention, indicating by appropriate arrows the flow of lubrication and purging liquid; and

FIG. 2 is a sectional view taken illustrating the lobe pump and porting arrangement of FIG. 1.

THE PREFERRED EMBODIMENT Referring now to the drawing, there is illustrated a pump assembly, FIG. 1, which includes a housing 12 having an inlet 14 and an outlet 16 connected respectfully to a source of liquid and a location of use of such liquid, both of which are not shown. To feed the liquid, which may and probably does contain solid contaminants, from the inlet 14 to the outlet 16, there are included in the housing 12, a centrifugal pump 18 and a lobe pump 20, both being commonly driven on a shaft 22 driven by a prime mover, not shown.

The lobe pump 20 has a primary section constituted by the crescent-shaped cavities 24, 26 in which blades 28 pump liquid from inlet ports 30, 32 to outlet ports 34, 36 and a secondary section in which the pump chambers are formed by the blades 28 moving in radial or substantial radial grooves 38 of the rotor 40 and which pumps liquid from inlet ports 42, 44 to outlet ports 46, 48. The blades 28 move outwardly by centrifugal force and hydraulic pressure such that the outer tips engage the walls of the cavities 24, 26. The outlet of the centrifugal pump 18 communicates with the primary inlet ports 30, 32 of the lobe pump 20. The primary outlet ports 34, 36 of the lobe pump 20 communicate with the outlet 16. Between the primary outlet ports 34, 36 of the lobe pump 20 and the outlet 16 is a self cleaning wash-flow filter 50 through which a minor portion of the liquid flowing therethrough passes to the inlet ports 42, 44 of the secondary section of the lobe pump 20 by way of passages 52. The major portion of the fluid flows to the outlet 16.

The secondary section of the lobe pump forces the relatively clean liquid from the wash flow filter along the grooves 38 formed by blades 28 and over the edges of the blades, over the ends of the rotor 40 along the bearing faces 56 of the pump port plates 58 which cooperate with the rotor 40 and cam ring 60 to form the cavities 24, 26 through bearing clearances 62, through spline clearances 64, and passages 66 to the low-pres sure area of pump inlet 14. Eventually the wash flow finds its way to the outlet 16 of the assembly FIG. 1.

The wash-flow filter 50 is self-cleaning because the main flow of liquid therethrough carries with it the solids deposited thereon.

As willbe obvious to one skilled in the art, a single lobe pump utilizing an arrangement of primary and secondary pump sections can be used in lieu of the double lobe pump just described, the primary and secondary sections being similarly formed.

While this invention has been described with reference to a particular arrangement, it is to be understood that the dual function pump can be used in other surroundings, as where two different flow requirements are desired, as for example, in an arrangement where a low-pressure flow is required for control purposes, or in other arrangement which will be apparent to those skilled in the art.

What. is claimed is:

1. A pump comprising:

a rotor in a housing having a primary inlet and a primary outlet and crescent-shaped pumping cavities;

said rotor being journaled for rotation in bearings and having slots therein;

means for rotating said rotor;

blades in said rotor slots movable outwardly by centrifugal force and pressure forces in said cavities to pump liquid, which is likely to include solid contaminants, from said primary inlet to said primary outlet;

a cylindrical self-cleaning wash-flow filter;

means for conveying the contaminated liquid from said primary outlet and along the axis of said wash flow filter;

a secondary pumping section defined at least in part by said slots and the inner portion of said blades;

a secondary inlet and a secondary outlet inwardly of the outer periphery of said rotor and communicating with said secondary pumping section; A

means for filtering a relatively small portion of the contaminated liquid through said wash flow filter to provide a source of clean liquid;

and means for supplying said clean liquid to said secondary inlet, the clean liquid thereby being pumped to said secondary outlet and in so doing cleaning the primary pumping section handling the contaminated liquid.

2. A dual function lobe pump having a primary pumping section and a secondary pumping section, said pump comprismg:

a housing having an inlet connected to a source of a liquid,

which is likely to include solid contaminants, and an outlet for said liquid;

a cavity in said housing;

a rotor having journals arranged for rotation in said cavity with its periphery defining therewith at least one crescent-shaped pumping chamber;

means for rotating said rotor;

inlet and outlet ports communicating respectively with said inlet and outlet and said pumping chamber;

radial slots in said rotor;

blades in said slots movable outwardly by centrifugal and pressure forces to pump the contaminated liquid through said pumping chamber and from said inlet to said outlet;

a secondary pumping chamber defined by the inner end of a blade and a slot;

a secondary inlet port and a secondary outlet port;

out said secondary outlet.

3. A pump as recited in claim 2 further comprising means communicating said secondary outlet with said journals for the passage of liquid for lubrication thereof.

4. A pump as recited in claim 3, further comprising bearing surfaces in said housing for said rotor and means communicating said secondary outlet with said bearing surfaces for the lubrication thereof. 

1. A pump comprising: a rotor in a housing having a primary inlet and a primary outlet and crescent-shaped pumping cavities; said rotor being journaled for rotation in bearings and having slots therein; means for rotating said rotor; blades in said rotor slots movable outwardly by centrifugal force and pressure forces in said cavities to pump liquid, which is likely to include solid contaminants, from said primary inlet to said primary outlet; a cylindrical self-cleaning wash-flow filter; means for conveying the contaminated liquid from said primary outlet and along the axis of said wash flow filter; a secondary pumping section defined at least in part by said slots and the inner portion of said blades; a secondary inlet and a secondary outlet inwardly of the outer periphery of said rotor and communicating with said secondary pumping section; means for filtering a relatively small portion of the contaminated liquid through said wash flow filter to provide a source of clean liquid; and means for supplying said clean liquid to said secondary inlet, the clean liquid thereby being pumped to said secondary outlet and in so doing cleaning the primary pumping section handling the contaminated liquid.
 2. A dual function lobe pump having a primary pumping section and a secondary pumping section, said pump comprising: a housing having an inlet connected to a source of a liquid, which is likely to include solid contaminants, and an outlet for said liquid; a cavity in said housing; a rotor having journals arranged for rotation in said cavity with its periphery defining therewith at least one crescent-shaped pumping chamber; means for rotating said rotor; inlet and outlet ports communicating respectively with sAid inlet and outlet and said pumping chamber; radial slots in said rotor; blades in said slots movable outwardly by centrifugal and pressure forces to pump the contaminated liquid through said pumping chamber and from said inlet to said outlet; a secondary pumping chamber defined by the inner end of a blade and a slot; a secondary inlet port and a secondary outlet port; filter means for deriving clean liquid from the pumped contaminated liquid; said secondary inlet port communicating with said filter means and said secondary pumping chamber at one position of said rotor; said secondary outlet port communicating with said secondary pumping chamber at another position of said rotor; whereby upon rotation of said rotor, clean liquid is pumped from said filter means through said secondary inlet to and out said secondary outlet.
 3. A pump as recited in claim 2 further comprising means communicating said secondary outlet with said journals for the passage of liquid for lubrication thereof.
 4. A pump as recited in claim 3, further comprising bearing surfaces in said housing for said rotor and means communicating said secondary outlet with said bearing surfaces for the lubrication thereof. 